For many years mixers with agitator shafts extending downwardly have been used to mix food items, such as milk shakes, right in a cup. More recently, similar mixers have been used to mix solid food chunks, such as candy and the like, into soft serve ice cream and other foods of similar texture. Since such mixers have permanent agitator shafts, frequent cleaning, most often between each use, is required because it is highly likely that each user will be blending different materials.
Such cleaning is quite time consuming for the commercial establishment which blends the product for the consumer and thus there is a need for a disposable agitator which could be quickly attached to the food mixer and readily and economically discarded after each use. The agitator shown in U.S. Pat. No. 2,833,576 represents an attempt to satisfy such need, however, it is impractical for many reasons. For example, were the device of that patent made of a material inexpensive enough to be economically disposable, the long unsupported agitator shaft would be so flimsy that first, it could not mix viscous food materials and second, at high speed operation it would flop around or oscillate outwardly possibly doing damage to the cup containing the food. In addition, the complex attachment of the agitator to the food mixer is not conducive to or compatible with the intended disposability. A retainer at the top of the shaft must be snapped into a plurality of metallic fingers having hooks thereon and then a spring is held by the hooks around the fingers. These metallic components with sharp edges also present a safety factor for the user whose hand could easily be injured were it to come into contact with the fingers or hooks spinning at high speeds.
Moreover, use of an agitator shown in U.S. Pat. No. 2,833,576 would be virtually impossible for the commercial establishment which invites the customer to blend his own product. In these instances the customer is given a cup and a spoon and he fills the cup with the food materials of his selection, uses the food mixer to blend the materials, and thereafter consumes the food with the spoon leaving the food mixer agitator contaminated with the remnants of his particular food material selection. If the commercial establishment were to provide the user with a spoon and the agitator according to the patent not only would the cost to the establishment be increased, and not only would the user be exposed to the problems and the hazards described above, but also the user would not be motivated to inconveniently remove the agitator and throw it away. Rather, he would leave it for the next user who might well, rather than removing the old agitator, throwing it away, and then assembling a new agitator, merely use the old agitator despite the potential contamination with foreign food materials.
Thus, to date, no one has developed an agitator assembly which is truly and economically disposable, which cannot represent a potential safety hazard to the user, and which by its configuration, will induce the user to remove it from the food mixer upon completion of the mixing.